A great deal of attention has been focused by the packaging industry on efforts with twist caps to achieve consistent closure sealing performance and consistent levels of capping torques. A basic problem exists with the construction of the closures and with the methods and machinery used to apply caps to containers. This problem results in large variations of the torque required by the consumer to remove such caps so that some demand unusual strength or special implements while others may be so loosely applied that the effectiveness of their seal has been compromised.
It is therefore an object of the invention to provide a closure system with superior sealing qualities.
It is a further object of the invention to provide a container neck finish with means for engaging a cap to provide superior sealing characteristics.